<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
</head>
<body>
	<p>数值选择器,value显示初始当前值</p>
	<form>
		<input type="range" step="2" min="0" max="20" value="8" />
	</form>
</body>
</html>